Will your engine survive when a sudden loss of radiator coolant occurs?

We’ve all been there or seen it happen at some time.  Driving down the road maybe on a vacation trip and a radiator or heater hose suddenly bursts and you’ve run out of radiator coolant.  Often times you won’t even notice the problem until a warning lights up on the instrument panel.

In my case, my smart car lost coolant and the engine overheated but never gave me an over temperature indication on the instrument cluster. Only when the coolant temperature sensor failed due to excessive heat in the cylinder head, did I get any indication that something was wrong with the engine. Unfortunately by then it was too late and severe damage occurred to the engine.

Now I would think that the coolant temperature sensor would indicated a problem if the coolant operating temperature was too low or too high but the sensor has to make contact with the coolant to get an accurate measurement. In this case however, the coolant stops making contact with the sensor so I’m assuming that some intermediate dry air temperature was probably measured so no trouble was seen by the sensor.

I realize that quite a few of you reading this already have a scan gauge II plugged into your OBDII port and can read coolant temperature but isn’t that temperature coming from the same coolant temperature sensor that I’m currently having issues with?

I know that this is a very common single point failure on any car with a coolant system. As these coolant systems age, I expect a whole lot more engine failures in the future. Other manufactures provide at least a low coolant indicator.  Others may have a secondary sensor monitoring the head temperature.  I would think that Mercedes/Mitsubishi engineering would have a solution that would give some indication of a problem long before engine failure. 

Tags: coolant, engine, failure, loss

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Watching the coolant reservoir "Max" and "Min" lines has worked for decades with countless numbers of other vehicles just fine.  A coolant level light is not necessary.  That's a feature that typically only expensive cars have.

Cooking an engine due to loss of coolant is generally due to a vehicle owners' failure to perform proper maintenance to a vehicle, not paying attention to warning signs. 

A coolant hose rubbing against something in the engine bay and randomly exploding is such a rare occurrence it isn't worth overhauling the way vehicles are designed.  If the hoses are checked every 10k, the hose deterioration will be discovered prior to failure.

That's not to excuse routing a coolant hose so close to something else that it rubs and causes accelerated deterioration.  In those cases, I would identify the issue at a smart service center and have it corrected prior to losing engine coolant.

Agreed, Putt Putt.  My "back to the drawing board" means frequent checks under the service flap in the front and under the engine cover in the back.  I have been lazy about the former.

Jim
 
Putt Putt said:

It's not unlike any other car on the road.  These are machines and machines are only as reliable as the maintenance performed on them.

Jim and Ann Brown said:

Very disturbing, to be relying on something which is not reliable.  Back to the drawing board.

Jim

How right you are, Kamaal.  My UltraGauge obviously made me sloppy about checking my coolant level, but I would still not be without it for many other reasons.

Jim
 
Kamaal Peterson said:

Watching the coolant reservoir "Max" and "Min" lines has worked for decades with countless numbers of other vehicles just fine.  A coolant level light is not necessary.  That's a feature that typically only expensive cars have.

Cooking an engine due to loss of coolant is generally due to a vehicle owners' failure to perform proper maintenance to a vehicle, not paying attention to warning signs. 

A coolant hose rubbing against something in the engine bay and randomly exploding is such a rare occurrence it isn't worth overhauling the way vehicles are designed.  If the hoses are checked every 10k, the hose deterioration will be discovered prior to failure.

That's not to excuse routing a coolant hose so close to something else that it rubs and causes accelerated deterioration.  In those cases, I would identify the issue at a smart service center and have it corrected prior to losing engine coolant.

Out of curiosity, what temperatures (range) did your UltraGauge display when it sensed coolant, and what temperatures did it display when it was detecting air pockets?  I imagine there would still be a difference in the temperature readings, or... no?

Jim and Ann Brown said:

How right you are, Kamaal.  My UltraGauge obviously made me sloppy about checking my coolant level, but I would still not be without it for many other reasons.

Jim
 
Kamaal Peterson said:

Watching the coolant reservoir "Max" and "Min" lines has worked for decades with countless numbers of other vehicles just fine.  A coolant level light is not necessary.  That's a feature that typically only expensive cars have.

Cooking an engine due to loss of coolant is generally due to a vehicle owners' failure to perform proper maintenance to a vehicle, not paying attention to warning signs. 

A coolant hose rubbing against something in the engine bay and randomly exploding is such a rare occurrence it isn't worth overhauling the way vehicles are designed.  If the hoses are checked every 10k, the hose deterioration will be discovered prior to failure.

That's not to excuse routing a coolant hose so close to something else that it rubs and causes accelerated deterioration.  In those cases, I would identify the issue at a smart service center and have it corrected prior to losing engine coolant.

I agree that doing routine maintenance and checks will avert 95% possibility of coolant loss.  We have on record however, some owners that experienced engine over heating and engine failure because of a failed water pump and others where the reservoir cap vibrated loose.  Something like that can happen anytime between routine checks and you’d never know it until engine failure.

I’m just saying that something as simple and cheap as a low coolant level indicator or a secondary sensor for engine temperature would prevent this other 5% possibility of destroying your engine.



Kamaal Peterson said:

Watching the coolant reservoir "Max" and "Min" lines has worked for decades with countless numbers of other vehicles just fine.  A coolant level light is not necessary.  That's a feature that typically only expensive cars have.

Cooking an engine due to loss of coolant is generally due to a vehicle owners' failure to perform proper maintenance to a vehicle, not paying attention to warning signs. 

A coolant hose rubbing against something in the engine bay and randomly exploding is such a rare occurrence it isn't worth overhauling the way vehicles are designed.  If the hoses are checked every 10k, the hose deterioration will be discovered prior to failure.

That's not to excuse routing a coolant hose so close to something else that it rubs and causes accelerated deterioration.  In those cases, I would identify the issue at a smart service center and have it corrected prior to losing engine coolant.

Kamaal,

My UG displays 190.4 F at 70 mph (74 indicated) on a moderately warm day in this part of the world, say 85-90F.  It occasionally drops down to 188.6 F for a while, and then back to 190.4 F.

In my ignorance I have figured that to most likely be the thermostat setting -- around 190 F.  Right?

I have my coolant temperature alarm set for 248 F.  I don't know where I got this number, but perhaps somewhere on the SCOA forum -- as I recall this was for a 2008.  I can't find anything in my Owner's Manual to help me with this.  Would you recommend a different alarm setting?

Munchkin is an unmodified 2011 Pure.  Coolant reservoir is midway between "Min" and "Max" when cold.

Tks much,

Jim 

Here’s what it says about coolant temperature in the 2008 and 2009 owner’s manuals:  The coolant temperature part is reworded in the 2010 and 2011 manuals and don’t include actual temperatures.

Coolant temperature

During severe operating conditions and stop-and-go city traffic, the coolant temperature may rise close to approximately 248F (120C).  The engine should not be operated with the coolant temperature over 248F (120C).  Doing so may cause serious engine damage which is not covered by the smart Limited Warranty.

Warning!

Driving when your engine is overheated can cause some fluids, which may have leaked into the engine compartment, to catch fire. You could be seriously burned.

Steam from an overheated engine can cause serious burns which can occur just by opening the front compartment cover. Stay also away from the engine if you see or hear steam coming from it.

Turn off the engine, get out of the vehicle and do not stand near the vehicle until the engine has cooled down.



Jim and Ann Brown said:

Kamaal,

My UG displays 190.4 F at 70 mph (74 indicated) on a moderately warm day in this part of the world, say 85-90F.  It occasionally drops down to 188.6 F for a while, and then back to 190.4 F.

In my ignorance I have figured that to most likely be the thermostat setting -- around 190 F.  Right?

I have my coolant temperature alarm set for 248 F.  I don't know where I got this number, but perhaps somewhere on the SCOA forum -- as I recall this was for a 2008.  I can't find anything in my Owner's Manual to help me with this.  Would you recommend a different alarm setting?

Munchkin is an unmodified 2011 Pure.  Coolant reservoir is midway between "Min" and "Max" when cold.

Tks much,

Jim 

FWIW, I set the UG alarm to 220 F just to be on the safe side.  Have never had it go off.

So will I, jwight.  I 'preciate the help by you and C&T.

Do either you have an idea what temp the thermostat is set for?  I would like this number just as a calibration check on the UG.  I dislike gauges which tell me something which may be wrong more than I dislike idiot lights.  So saith a pilot.

Jim

I do not believe this is a slow leak problem, but a sudden and rapid loss of coolant.   According to your statement I should pull over every 5-10 minutes and check the reservoir "Max and Min".    Why would the dealership check that hose for wear since it is not a problem?   It's not a normal check.     The smart thing to do now is to issue a recall and inspect and replace the hose and cap.

Kamaal Peterson said:

Watching the coolant reservoir "Max" and "Min" lines has worked for decades with countless numbers of other vehicles just fine.  A coolant level light is not necessary.  That's a feature that typically only expensive cars have.

Cooking an engine due to loss of coolant is generally due to a vehicle owners' failure to perform proper maintenance to a vehicle, not paying attention to warning signs. 

A coolant hose rubbing against something in the engine bay and randomly exploding is such a rare occurrence it isn't worth overhauling the way vehicles are designed.  If the hoses are checked every 10k, the hose deterioration will be discovered prior to failure.

That's not to excuse routing a coolant hose so close to something else that it rubs and causes accelerated deterioration.  In those cases, I would identify the issue at a smart service center and have it corrected prior to losing engine coolant.

It's all about numbers.  Does anyone know the actual number of 2008 smarts that have had the hose rub through with a resulting engine failure?  I don't, and I doubt if anyone on this thread does.  Of that unknown number, how many were reported to the NHTSA? Only smart USA knows for sure, and since most of the unknown number of events would have happened when PAG was running the show I doubt if that info was passed along to smart USA/DVI.  As for the cap coming off on its own - take a look at your cap and see what you think; my opinion is the chance of the cap coming off spontaneously is slim to none.

David Scott said:

I do not believe this is a slow leak problem, but a sudden and rapid loss of coolant.   According to your statement I should pull over every 5-10 minutes and check the reservoir "Max and Min".    Why would the dealership check that hose for wear since it is not a problem?   It's not a normal check.     The smart thing to do now is to issue a recall and inspect and replace the hose and cap.

Kamaal Peterson said:

Watching the coolant reservoir "Max" and "Min" lines has worked for decades with countless numbers of other vehicles just fine.  A coolant level light is not necessary.  That's a feature that typically only expensive cars have.

Cooking an engine due to loss of coolant is generally due to a vehicle owners' failure to perform proper maintenance to a vehicle, not paying attention to warning signs. 

A coolant hose rubbing against something in the engine bay and randomly exploding is such a rare occurrence it isn't worth overhauling the way vehicles are designed.  If the hoses are checked every 10k, the hose deterioration will be discovered prior to failure.

That's not to excuse routing a coolant hose so close to something else that it rubs and causes accelerated deterioration.  In those cases, I would identify the issue at a smart service center and have it corrected prior to losing engine coolant.

Just came out from under my 2008 Passion, (build date 1/08)  The hose is scuffing badly.

Not much room to move for a pix, or a fix ,without a hoist, or at least a 2-3 ft jack up on the passenger side..

Hose is hidden DEEP in a small space near the trailing edge of the belly pan, Passenger side.  If you were to draw a line around the bottom, to the top of the car it would end up right around the divider to the front and rear windows. in other words ,almost mid ships.

If you have an 08 or an 09 Look at this before you drive again.  You may save your engine.  A2Jack

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